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(No Model.)

P. B. CHARBONEAU.

` SAW SWAGE. No. 287,363. K Patented Oct. 23, 1883.

diffe/S: v y;venzzobrf ai'. z/yczlzaraneau PETERS. mwumnmvner. washmgcmnl;

' Nrrno STATES PATENT rrr-ron.

PASCAL B. CHARBONEAU, CF BAY CITY, MICHIGAN, ASSIGNCR OF TWC- THIRDS TCH. A. FRASER AND J. B. BARBER, BOTH OF SAME PLACE.

f sAw-swAG. I

SPECIFICATION forming pare of Letters Patent No. 287,363, dated october23, 1883.

Application filed May 10, 1883. (No model.)r

To all whom, it may concern,.-

v Be itknownthat I, PiiscALB. GHARBONEAU',

of Bay City, in the county of Bay and State of llIichigan, have inventednew and useful Improvements in Saw-Swages; and Ido hereby declare thatthe following is a full, clear, and exact description of the invention,reference being had to the accompanying drawings, which form a part ofthis specication.

This invention is an improvement in sawswages; and it consists in theconstruction and arrangement of parts, as will be more fully hereinafterset forth, and specically pointed out in the claims.

At the present state of the art swaged sawteeth are generally formed byupsetting the tooth, so as Ito spread itsv cutting-edge, or a form ofpunch or striker has been used whichv forms a flattened saw-tooth. Theobjection to the method of upsetting the tooth is that the steel whichforms the cutting-edge of the tooth is thereby inj uriously affected, asthe fibers or particles of steel lose some of their cohesion,

making the steel, as it is technically called,

coarse.77 lVhere the lsaw-teeth are much worn, the operation ofupsetting has to be preceded by filing, so as to bring the saw-tooth inproper shape for upsetting. The swage-tooth obtained by punching devicesis weak and necessitates much filing.v Ageneral objection to all presentdevices of forming swage-teeth is that they all affect the cutting-lineof the tooth,

which necessitates a readjustment by filing,

which in circular saws with inserted teeth is a serious drawback.

ing ysaw-teeth the cutting-line of the tooth is never affected, and thetooth is formed by an operation which is just the reverse fromupsetting, and tends to refine the steel which 4o makes up thecutting-edge, instead of destroying its cohesion, as in the upsettingprocess.

Another advantage is that I am enabled to form a superior swage-toothwith less loss of material, as the amount of filing needed to perfect mytooth is but trifling, as will be shown and explained hereinafter.

In the drawings, Figure l shows in diagram the operation of swaging atooth of an ordinary mill-saw. Fig. 2 shows the operation of 5o swagingan inserted tooth of a circular saw.

` filing.

lVith my means for swaglvFig. 3 is aside elevation and top plan of thesame tooth after swagin'g. Fig. 4L isa side' elevation of the same toothwhen perfected by In Fig. 1, A is the tooth of an ordinary millsaw,which is intended to be swaged. B is a bed tool or anvil to support thetooth. C is a die, which is provided witha segmental cylindrical face,a'. This die is forced down by pressure upon the tooth, as shown bydotted arrow. The action of the die C will be easily understood from thedrawings. Its rounded portion a will form an indentation, b, on top ofthe tooth, pressing a corresponding amount of material toward thecutting-edge and producing the desired spread or display, as the shapeof the die does not allow the material to escape'any other way. To getthe proper effect, the die C is held in proper guides, or otherwise, soas to allow it to move only in the direction it is intended to act. Thebottom die or anvil, B, serves as a rest only, and furnishes a largeenough support and resistance against the pressure brought to bearagainst Vthe top die, so as not to alter or affect the cutting-line c ofthe saw. Its bearing or supporting surface does not extend beyond thecutting-edge, thereby aiding and Yfacilitatin g the action of the vupperdie, which, with sufficient pressure, can now form an almost finishedcutting-edge, which 'requires only a few strokes of a file to form aperfect chisel-edge.

In Fig. 2 is shown the arrangement of the dies for swaging the teeth ofa circular saw. The form of the dies is reversedthat is, the bottom orstationary die is provided with the segmental cylindrical face, whilethetop die is provided with a plain inclined face. The top die is broughtdown upon the tooth, the same as in Fig. l, but the indentation will nownaturally be produced on the leading face of the saw-tooth; but theresult is again a swagetooth of the same conformation as in Fig. l,necessitating only a few strokes of a file to acquire the chisel-edge.It will be seen that (the saw being free to rotate) the top tool merelypresses the saw-tooth onto the lower, without in the least affecting thccutting-line of the tooth, if it is given only enough bearing-surface.This is a decided advantage of my proroo cess, especially for swagin ginserted teeth. After swaging, allY the filing needed is simply tosharpen the cutting-edge, which generally has only a little burr, ifthefoperation has been performed with any care. As the tooth is providedwith an 'indentation back of its cuttingedge, the iling will produce aregular chiseledge, as seen in thedrawings. This is a feature notproduced by any other manner of swaging. The nature of the indentation,produced as it isby a perfectly-smooth die, is of itself a desirablefeature in my swage-tooth, as it greatly facilitates the escape of thesawdust, its smoothness making it superior to any similar indentationobtained by the use of a iile.

The use of the segmental cylindrical die-face I consider an importantfactor, as it furnishes a tooth that presents amost favorable cuttingedge-thatis a chisel-edge-the action of which is greatly assisted by thesmooth indentation into which it leads the dbris.

whole adapted to swage a recess in the face of 35 the tooth in the rearof the Vcutting-edge and spread the metal on either side thereof, as setforth.

PASCAL B. CHARBONEAU.

Vitnesses: i Y H. S. SPRAGUE,

E. SCULLY.

